This invention relates generally to surgical devices and, more particularly, to an improved elastic ligature applicator having a central member for storing a plurality of elastic ligatures in series and in an unexpanded state, an elastic ligature conical expander and a ligature dilator for pushing a ligature over the expander and onto grasped anatomical tissue. An optional handle assembly facilitates manipulation of the applicator during a surgical procedure. Components are readily assembled and disassembled to load a new supply of ligatures into the applicator.
Several prior art patents and pending applications are directed to somewhat similar applicators. U.S. Pat. No. 4,167,188 issued to Coy L. Lay, deceased, et al only discloses an elastic band designed and dimensioned for tying off human Fallopian tissue or similar anatomical tubular tissue. My own prior U.S. Pat. No. 4,548,201 is directed to an improved, elastic ligating ring clip and a ring loader for placing elastic rings onto the distal end of a ring applicator. The loader includes a conical ring expander and a ring dilator in the form of thin, flexible parts joined in pairs radiating from a deformable, elastic ring engaging aperture.
Relating pending applications include my copending U.S. applications Ser. Nos. 049,503, filed May 14, 1987, now U.S. Pat. No. 4,788,966, and 063,913, filed June 19, 1987 now U.S. Pat. No. 4,860,746. The former application concerns multi-functional instruments for surgical procedures including improved stretchable ligating and occluding devices, an applicator and an expanding and loading device somewhat similar to that disclosed in my prior U.S. Pat. No. 4,548,201. The latter application is directed to improved elastic ring clips, with which the present invention may be used, and an improved loading device for expanding and loading an elastic ring onto an applicator, in an expanded state.
Elastic rings or ligatures with which the present invention may be used may be made from a wide variety of known absorbable and non-absorbable materials which are discussed in detail below. A problem that has been noted is that at least some of these materials have an abbreviated elastic memory life. In other words, if rings or ligatures made of elastic material are stretched or expanded and left on the applicator for too long a period of time, then the elastic memory of the material may be impaired so that, when an elastic ligature is placed onto anatomical tissue, it may not return to its initial shape or configuration. Thus, the intended ligating or occluding function of the ligature may be impaired.
The present invention, in direct contradistinction to prior devices, provides an elastic ligature applicator for storing a series of ligatures in a substantially unexpanded state. The ligature is stretched or expanded only immediately prior to placement of the ligature onto anatomical tissue. Thus, the possibility of impairment of the elastic memory characteristic of the material from which the ligature is made is reduced to a virtual nullity.